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Swift Observations of SN 2009N in NGC 4487

ATel #1914; S. Immler (NASA/CRESST/GSFC) and P. J. Brown (PSU), on behalf of the Swift satellite team
on 27 Jan 2009; 16:48 UT
Credential Certification: Stefan Immler (immler@milkyway.gsfc.nasa.gov)

Subjects: Optical, Ultra-Violet, X-ray

Referred to by ATel #: 1915, 1925

The Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT) on board the Swift satellite started observing supernova 2009N in NGC 4487 (CBET #1670, #1671) on 2009-01-27.63 UT. The following UVOT magnitudes were measured: v = 16.3±0.1 (355 s exposure time), b = 16.4±0.1 (355 s), u = 15.5±0.1 (355 s), uvw1 [181-321nm] = 16.1±0.1 (711 s), uvm2 [166-268nm] = 16.4±0.1 (940 s), uvw2 [112-264 nm] = 16.5±0.1 (1423 s). These magnitudes are on the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) which in the optical is close to the Johnson UBV, and have not been corrected for extinction. The UV-optical colors are similar to SNe IIP about one week after explosion (cf. Dessart et al. 2008, ApJ, 675, 644).

No X-ray source is detected at the position of the SN in the 4.4 ks Swift XRT observation obtained simultaneously with the UVOT observations. The 3-sigma upper limit to the XRT net count rate is 1.7E-03 cts/s, corresponding to an unabsorbed (0.2-10 keV band) X-ray flux of <8.0E-14 erg/cm/cm/s and a luminosity of <2.0E39 erg/s for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of N_H = 2.33E+20 (Dickey & Lockman, 1990, ARAA, 28, 215) and a distance of 15 Mpc (z=0.003449, Koribalski et al. 2004, AJ 128, 16, from NED; H_o = 71 km/s/Mpc, Omega_M = 1/3, Omega_L = 2/3).

Swift image of SN 2009N